When Texas entered the Union it outraged the Mexican government. It broke diplomatic relations with the United States. It got worse when America and Mexico disputed on the southwestern border. In November 1845, president Polk sent John Slidell to Mexico City to try and purchase California and resolve other differences, but president Jose Joaquin refused to meet with him. Then on January 1846 General Zachary Taylor led troops into territory claimed by the U.S. and Mexico. Then after defeating Mexico the Treaty of Guadalupe Hidalgo . It gave the U.S. more than 500,000 square miles of territory.
When Texas entered the Union it outraged the Mexican government. It broke diplomatic relations with the United States. It got worse when America and Mexico disputed on the southwestern border. In November 1845, president Polk sent John Slidell to Mexico City to try and purchase California and resolve other differences, but president Jose Joaquin refused to meet with him. Then on January 1846 General Zachary Taylor led troops into territory claimed by the U.S. and Mexico. Then after defeating Mexico the Treaty of Guadalupe Hidalgo . It gave the U.S. more than 500,000 square miles of territory.